CVE-2026-20100
Reported by cisco · Published March 4, 2026
A vulnerability in the LUA interperter of the Remote Access SSL VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with a valid VPN connection to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This does not affect the management or MUS interfaces. This vulnerability is due to trusting user input without validation in the LUA interprerter. An attacker could exploit this vulnerability by sending crafted HTTP packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
Risk scores
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Cisco | Cisco Secure Firewall Adaptive Security Appliance (ASA) Software | 9.12.1, 9.12.1.2, 9.12.1.3 |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 6.4.0, 6.4.0.1, 6.4.0.3 |
| Cisco | Cisco Secure Firewall Adaptive Security Appliance (ASA) Software | 9.12.1, 9.12.1.2, 9.12.1.3 |
| Cisco | Cisco Secure Firewall Threat Defense (FTD) Software | 6.4.0, 6.4.0.1, 6.4.0.3 |
Timeline
- Mar 4, 2026 CVE Published
- Mar 4, 2026 PoC Published (5 in total, the first dated here)
- Mar 5, 2026 EPSS Score (30 in total, the first dated here)
- Mar 17, 2026 Security Advisory (3 in total, the first dated here)
- Mar 25, 2026 Coalition ESS Score (2 in total, the first dated here)
Query this with the API
The same record, from the CLI:
vulnetix vdb vuln CVE-2026-20100
vulnetix vdb fixes CVE-2026-20100Or with curl, using the org id and key from your account page:
curl -s -H "Authorization: ApiKey ${VULNETIX_ORG_ID}:${VULNETIX_API_KEY}" \
"https://api.vdb.vulnetix.com/v2/vuln/CVE-2026-20100/fixes/registry"The Community plan is free and allows 50 queries a day. Get a free API key · API quickstart